Luminous paints, such as fluorescent paints, blacklight paints, and phosphorescent paints, include a wide range of pigments that glow or otherwise emit visible light when exposed to an energy source such as ultraviolet (UV) light radiation, e.g., wavelengths between 400 nm to 10 nm. Blacklight paints can be applied to a variety of surfaces so that those surfaces will glow in different colors when illuminated by UV light. The surface glows because the blacklight paint converts UV wavelengths into visible wavelengths. For example, blacklight paints may be painted on surfaces of dark amusement rides in theme parks or entertainment parks to create a glow-in-the-dark effect.
Blacklight paints generally require the use of external UV sources, such as UV light emitting diode (LED) strobes, UV lamps, or the like to provide the UV radiation. In certain instances, such as when used in entertainment attractions, these external UV sources may often be required to be hidden from being viewed by guests to maintain the aesthetics and experience of the attraction.
Additionally, for complex or irregular surfaces multiple UV lamps may be needed to light the surfaces from various angles and locations to ensure uniform exposure to the UV radiation and thus a uniform luminous appearance. FIG. 1A is a simplified diagram illustrating a flat surface glowing in the dark with external UV sources. As shown, three external UV sources 102A-C are placed at different angles and locations from the surface 104, which is covered with blacklight paint. When the UV sources 102A-C are turned on, the 2D surface 104 glows due to the reaction with the UV sources. FIG. 1B is a simplified diagram illustrating a three dimensional surface glowing due to the UV emitted from the external UV sources. As shown, the three dimensional (3D) surface 106 glows when three external UV sources 102A-C emit UV radiation that impacts the 3D surface 106. The multiple UV sources are required for the 3D surface to ensure that every curve and shape of the structure receives the UV radiation and emits a uniform level of light. Because the UV wavelengths emitted from the UV lights are typically invisible to humans, the illuminated surfaces appear to “glow in the dark” when visible light sources are turned off or not present.
Even with multiple UV sources, light uniformity may still be a problem for illuminating very curved or convoluted surfaces because the complex geometry or shapes of the objects may prevent UV light from being received in certain areas. That is, certain structures of the shape block the UV radiation emitted from the external UV source from reaching other areas. This limits the creative freedom or flexibility by artists. Also, people and other structures cannot get close to these surfaces as anything casting a shadow may prevent the UV light emitted from the UV source from reaching the blacklight paint, which may then cease to glow.
External UV sources also do not allow precise illumination control, such as to illuminate small details such as a nose of a face of character. This is because the light emitted from an external source is likely to bleed onto other areas of the surface.
Additionally, UV light or radiation from external UV sources may also inadvertently cause other items to change in appearance or glow. This side effect may adversely impact the aesthetics of an application, such as dark theme park rides that include blacklight painted surfaces. For example, white shirts may glow in the dark if exposed to UV light in a dark setting as typically white shirts may be laundered with a bleaching agent, such as detergent containing bleach. This bleaching agent may glow when exposed to UV light, because many bleaching agent contain chemicals that emit visible light when exposed to UV light. This inadvertent glowing in certain environments, such as theme parks, may diminish an intended artistic effect, as the artist may wish that only the object of interest glows in the dark environment and that other objects.
UV light from external UV sources may also scattered onto people's faces, which may enhance the visibility of some undesirable characteristics. For example, dirt on a person's teeth may be visible in a dark setting when the UV light is scattered onto the person's face, as the person's teeth absorb the UV light and reemit light having a longer wavelength, i.e., visible light, causing the teeth to glow.
It is with these shortcomings in mind that the present disclosure has been developed.